Conventional light emitting semi-conductor (LES), including light emitting diodes (LEDs) and laser diodes, and LES devices (LESD) and packages containing LESDs have several drawbacks. High power LESDs generate a substantial amount of heat that must be managed. Thermal management deals with problems arising from heat dissipation and thermal stresses, which is currently a key factor in limiting the performances of light-emitting diodes.
In general, LES devices are commonly prone to damage caused by buildup of heat generated from within the devices, as well as heat from sunlight in the case of outside lighting applications. Excessive heat buildup can cause deterioration of the materials used in the LES devices, such as encapsulants for the LESDs. When LESDs are attached to flexible-circuit laminates, which may also include other electrical components, the heat dissipation problems are greatly increased.
When LESDs are packaged into sub-mount devices, which are then attached to secondary driver systems such as metal core PCB (MPCB), metal insulated substrate (MIS), Bergquist thermal boards, COOLAM substrates, etc., the thermal performance of the submount depends on the thermal resistance of each element in the structure including the sub-mount device, the secondary driver, and the heat sink. In many cases, the secondary driver limits the thermal performance of sub-mount device. Consequently, there is a continuing need to improve the design of support articles and packages to improve their thermal dissipation properties.